Sounding signal device



Nov. 1, 1938. R M

CRITCHFIELD 2,135,328

SOUNDING SIGNAL DEVI CE Filed May 5, 1934 I I I g; .i'lll llllllll, a w

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Patented Nov. 1, 1938 I I UNITED ,s'r as PATENT orries SOUNDING SIGNAL DEVICE Robert M. Critchfield, Anderson, 1nd,, assignor to General Motors Corporation, Petroit, Mich., a corporation of Delaware 1 Application May 5, 1934,: Serial No. 724,010

15 Claims. (01. 177 1) This invention relates to sound 7 signals and screw 21 to astirrup 28 which is in turn secured more particularly to horns for automotive vehito the peripheral flange 22 by screws not shown. cles of the type in which a movable assembly is TWo of the screws 23 maybe used to accomplish actuated by, an electromagnet energized by a this. The main housing -25-has a reduced or suitable source of current. necked portion 29 that is internally threaded for 5 One of the objects of the present invention is receptionof a bushing 30 havingan aperture 3! the production of a signal device which provides :within which isattached in any-suitable manner means for self-aligning or automatic adjustment a projector body or trumpet 32 including -a bell, of the movable parts thereof. I amplifier or. flared opening 33.

Another object of the invention is to simplify --A diaphragm '34 is firmly secured at its periph- 10 the construction as well as the means and mode ery by screws 23 between the flanges .22 and 24 of operation of sound signal devices, whereby they of motor housing 2| and main housing or collar will not only be cheapened in construction, but :25 respectively, and at its centralportion carries will be more efficient in operation, capable of be- .a pair of clampingplates 35 and 35 held by rivets ing easily and quickly adjusted, and less likely to 31, by which the central portion of the diaphragm 15 get out of repair. is stiifened l Another object aside from accomplishing a a The magnet motor comprisinga field frame self-aligning of the motor and armature, is to 38, a winding-39 and an armature 40, receives provide simplified means for adjusting both the through its central portion a rod or bolt 4| that 20 motor air gap, and the piston air gap, through a ,carries a sleeve 42 threadedly' engaging at its 20 single agency. one end the diaphragm 34 and clamping plates A further object is to provide means whereby .35 and'36,;and at its other end threadedly receives the air-flow gap of an air tone horn may be nicely a bushing or sleeve 43. On the bushing there is adjusted to attain the infinitely close approach mounted a piston or tone disc 44, that is secured or possible light engagement of air impeller and by peening overthe end of the bushing or sleeve 25 collar that makes for clarity and purity of tone. 43 at 45 againsta washer 46. l l

These objects are accomplished by forming a The sleeve 42 has internal conical surfaces 41 ball and socket mounting for the armature on its and 48 cooperating respectively with a nut 01' spindle, and by providing an expansible sleeve for wedge 49 whose conical surface 49a engages the connecting the armature to the movable assemconical surface 41 of the sleeve, and with another 30 bly, which sleeve cooperates with expanding memwedge member 5|] having a conical surface 5% bers and a clamping nut to secure the parts in that engages the conical surfaces 48 of the sleeve adjusted relation. 42. The nut 43 is threadedly connected to the With the above objects in view, the invention bolt 4| extending through the member 50 and resides in those novel features of construction, the sleeve, as-well as the armature 49. On 35 combination and arrangement of parts, which the opposite side of wedge member 50 is a spheriwill be hereinafter first fully described, and then cal-like projection 5| which engages or fits into be specifically pointed out in the appended claims, a concavity 52 of like contour formed in the arreference being had to the accompanying drawmature 40. The end portions of'sleeve 42 are ing, illustrating a preferred and practical but split radially at 53 and 54 respectively for provid- 40 obviously not the only embodiment of my invening yieldable clamps for the wedges $9 and 5B. ticn, i Located on the reverse side of the armature 40 In the drawing: 7 preferably integral withthe rod or bolt 4! and Fig. 1 is a view of a sound signal embodying the movable in unison with the wedge member 50,

present invention, partly in longitudinal section there is an abutment or collar 55 that-has a and partly in elevation. spherical concave surface 56 that engages a Fig. 2 is an enlarged sectional view taken on rounded surface 51 of a washer 58 disposed about line 2-2 of Fig. 1. i the rod 4| and located between the armature 49 Fig. 3 is a view taken on line 33 of Fig. 1. and the collar 55. Referring to the drawing, a magnet motor 20 is The movable assembly has its support com- 5 mounted upon a motor housing 2| by screws Zia, pleted by means of a return spring 59 centrally and the housing 2| is attached through its periphapertured at 59a to receive the reduced end of eral flange 22 by screws 23 to flange 24 ofa main rod 4|, the spring being anchored at its ends 5% housing or collar member 25. A shell 26 enclosby screws 59c driven into the housing member 2| {5'5 ing the magnet motor 20 is firrnly secured bya Jor elsewhere. The diaphragm assembly and the the assembly relative to the which support is yielding and operative to return the movable assembly from the actuated position due to the magnet.

An extension 31a of one of the rivets 31 in the diaphragm clamping plates35 and 36, provides means for an actuatorfor a circuit breaker mechanism now to be described.

' The contact breaker assembly, as shown in Fig.

1 includes rivets upon which are mounted in the order mentioned, a fixed contact plate or bracket 60 carrying a contactil, a nonconducting strip 62, a resilient plate 63 supporting a movable contact 64, a connector plate 65, an insulator strip 66,

an adjusting plate 61 and supporting spring plate I 68. By this means the contacts are properly insulated, and after these members have been assembled, the rivets are peened over as at 69, thus holding the parts in place.

The relative position of the'contact breaker assembly with respect to the motor frame 2|, is determined by an adjusting screw that is threadedly received in the motor'frame 2| so-that the screw comes into engagement with the end of the adjusting plate 61 previously described and is capable of adjusting the contact assembly by twisting of the spring plate 68.

It is obvious that running the screw Ill in or out will operate to move the end of the plate 61 and with it the bracket 60, thus varying the relation between the resilient plate 63 and nonconducting strip 62 with respect to pin or actuator 31a. Once the adjustment is made by the screw 19, tightening of the nut H will maintain the adjustment of motor frame 2I.

Another of the rivets 31 securing thecla'mping discs35 and 36 to the diaphragm is providedwith an extension, as 3112 of sufficient length to project across the space between the diaphragmassembly and the armature 40 and be received by a recess 40a in the opposing face thereof. These provisions afford locating means to insure that the armature will be maintained inproper orientation with respect to the field frame 38, irrespective of the adjusted space between the armature and diaphragm. The disclosed improvement makes for proper control of the armature alignment the spacing of the motor air gap A, and the piston air gapB. It is more or less essential that these gaps be small, and that each be independently adjustable. ,One element, of success in an air tone horn, of which the disclosed embodiment is one form, is the high frequency with which the movable assembly can be actuated. Hence, an airgap of small dimension at A, between the field irame and armature, makes for high frequency operation. Another element of success is the nice adjustment of the air gap at B between the piston ordisc and its cooperating collar. This should be so exactly adjusted that when the movable assembly is actuated, the piston will just about engage the collar on the compression stroke, but will not strike it so firmly as to click or produce any metallic sound.

It is indeed difficult to ascertain when the unit is in operation whether or not the piston mem ber 44 actually engages the collar member 25. If there is actual physical engagement between these members, that engagement must be so slight as to fall short of producing any metallic click or noise of operation, yet the approach of piston toward the collar must be so marked that there will be a sharp cutting off or stopping of air fiow. It therefore appears, and in fact is appllcants theory that the piston-collar relation when the impeller is at the extreme of the compression stroke, is one of infinitely close approach, or of infinitely light engagement. This view obtains as to all typesof air impeller devices for stopping and vibrating air columns of sound signals, and the improvement is effective in that form where the impeller device meets the collar member in substantial surface engagement, as well as in the form illustrated where the opposed faces of the impeller and collar are slightly divergent and are in but line-like engagement at some part of the cooperating impeller and collar. In all events, when the magnetic gap and the air-flow gap are adjusted to accomplish these proposed relations, the eificiency of the sound signal device is a marked improvement over the results obtained if the adjustment is "otherwise. The means disclosed for accomplishing this adjustment are particularly effective in accomplishing the desired results for by such anadjusting means it is possible to substantially eliminate all of the vibrations set up'in the element 44, or at least all audible vibrations are thought to be dampened. At any event the resultant tone product is one of a vibrating air column and is one that is free of any mechanical noise.

The manipulation of the device for the alignment of the magnet motor and the adjustment of to the diaphragm 34 or the disc 44 may be turned relative to the sleeve 42, in order to vary the distance between the diaphragm and thearmature,

or between the disc and the housing member 25. When the proper adjustment is made, the movable assembly is pushed down against the field frame 38 whereupon the armature 40 will oscillate or pivot on its ball and socket support, and

rest fiat upon the frame.- The nut 49 is then tightened, forcing the slotted portions 53 and 54 outwardly, thus clamping the sleeve 42 in the adjusted position.

It may not be necessary to make all of these ad justments at a single instance. The desire or necessity for adjustment may in part, embrace only one of those set out, that is, eitherthe armature alignment or the magnetic air gap at A, or the 'air flow gap at B. The armature align-' ment is self-correcting, in that an armature relation with the frame member that is not in correct alignment, will'be automatically established through the operation of the magnet motor, since a high point of the armature will continually hammer on the frame until the armature oscillates on its balland socket support until it lies substantially flat or parallel with the frame. When adjusting the magnetic or A gap only, the nut 49 is loosened and then holding the disc 44, the sleeve 42 is run in or out. This varies the space between the armature and the diaphragm assembly and consequently the space between the armature and the magnet frame, 7

B p. the sleeve 42 vary the spacing of the disc 44 with respect to the diaphragm assembly and the casing member 25, since the diaphragm assembly and the housing member 25 are relatively fixed parts when the movable assembly is at rest. This form of adjustment is particularly valuable in sounding signals of the air tone type, where it is desirable to control the oscillatable movement of the movable assembly so that the air column through the trumpet may be set into vibrations by the disc 44, without the contribution of mechanical noise from the movable structure due tohammering or clicking'of the mechanical elements. The foregoing disclosure is-towbe regarded as descriptive and illustrative, only, and notias a restriction or limitation of the invention, for obviously, an embodiment constructed to include modification without departing from the gen eral scope herein indicated and denoted'in the appended claims could well be made. While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow. 1 l What is claimed is as follows: 1. In a sounding signal, an air impeller device comprising in combination,-a diaphragm, a disc and an armature, means adjustably uniting the diaphragm, disc and armature into a single oscillatable assembly and comprising in combination, a rod having-a universal joint connection with the armature, a sleeve having internal conical surfaces and provided with external surfaces threaded into the diaphragm and disc, conical wedges cooperating with the conical surfaces of the sleeve to force the sleeve ends into binding engagement with the disc and diaphragm, one of said wedges being threaded upon the rod end for securing the parts in adjusted relation.

2. In a sounding signal, an air impeller device comprising in combination, a diaphragm, a disc and an armature, means adjustably uniting the diaphragm, disc and armature into a single oscillatable assembly and comprising in combination, an armature rod for supporting the armature, a sleeve having expansible end portions threaded each into the diaphragm and-the disc and slidably disposed over the annature rod, a wedge device disposed against the armature and engaging within an expansible end of the sleeve, a second wedge device threaded upon the end of the armature rod and engaging the second expansible portion of the sleeve, said sleeve portion threaded within the diaphragm forming an adjustable abutment for the armature, and being capable of rotation with respect to the diaphragm so as to vary the magnetic air gap, and the second wedge providing meansfor securing the parts of the movable assembly in the adjusted position.

3. In a sounding signal, an air impeller device comprising in combination, a housing, a field frame carried by the housing, a diaphragm, a disc and an armature, means adjustably uniting the diaphragm, disc and armature into a single oscillatable assembly and the v v ating with the field frame to form a magnetic air gap and the disc cooperating with a portion of the housing to provide an air flow gap, said assembly comprising in combination, an armature rod for supporting the armature, a sleeve having expansible end portions threaded each into the diaphragm and the disc and slidably disposed over the armature rod, wedge devices caring the'relation of the threaded into the armature cooper- I ried by the rod and each engaging an expansible end portion of the sleeve, said sleeve being rotatable on the rod and within both the diaphragm and disc for varying the magnetic air vmovable assembly into rigid and secure relation.

4. In a sounding signal of the vibratory type, a motor, a projector, a movable assembly interposed between the motor and the projector and arranged to provide a magnetic air gap between one side thereof and the motor and an air flow gap between the other side thereof and the projector, means uniting the elements of the movable assemblyinto a composite unit and for varymagnetic gap and the air flow gap comprising in combination, a yieldable support, an armature disposed on. one side of the magnetic gap, a piston disc disposed on one side of the air flow gap, said uniting means including an armature rod, a threaded sleeve with expanding end portions threaded into the diaphragmand disc and slidable on the rod, and wedging members carried by the rod for expanding the ends of the sleeve into engagement with the diaphragm and disc respectively, one of said \vedging members being disposed between the armature and diaphragm and forming a universal joint connection for the armature, the other of said wedging members being threaded upon the rod and engaging the other expanding portion of the sleeve for tightening all of the elementsof the movable assembly into rigid relation; V

, 5. In a sounding signal having a projector, a motor, and an air impeller for vibrating the air column of the projector, said impeller comprising a diaphragm, a piston disc, and an armature for actuating the diaphragm and disc, means for defining the relations of the elements of the impellencomprising, a rod supporting thearmature, meansv for adjustably connecting the rod'to the diaphragm and the disc, said means including a sleeve having expansible end portions diaphragm and disc and being loosely carried by the rod, wedging members sliding on the rod and cooperable with the ex pansible portions of the sleeve, and means including one ofthe Wedging members for forcing the. sleeve into relatively nonr'otative engage-- ment with the diaphragm and disc.

. 6. Ina sounding signal having a projector, a motor, and an air impeller for vibrating the air column of the projector, said impeller comprising a diaphragm, a piston disc, and an armature for actuating the diaphragm and disc, means for defining the relations of the elements of the impeller comprising, a rod supporting the armature, means for adjustably connecting the rod to the diaphragm and the disc, said means including a sleeve having expansible end portions threaded int-o the diaphragm and the disc and slidable alo'ng the rod, expanding members also carried by the rod and each engaging an end of the sleeve, and means for forcing the expanding members within the ends of the sleeve for retaining the contributing parts of the impeller in relatively fixed relation.

7. In a sounding signal having a projector, a vibration motor, means for supporting the pro-- jector and motor, and a movable assembly located between the motor and the projector and air column in the projector, the combination of means for adjusting the magnetic air gap and the air flow gap independently comprising in combination, an armature rod, an armature carried by the rod,' an expansible sleeve threaded into the parts of the movable assembly and slidable on the rod, said sleeve being rotatable relative to the elements of the assembly so as to alter their spaced relation, and means for looking the sleeve in the adjusted position whereby the magnetic air gap and'the air flow gap are each positively defined.

'8. In a sounding signal of the vibratory type, the combination of, a motor, a movable assembly comprising, a diaphragm, an armature operable by the motor, a rod supporting the armature and connecting it to the diaphragm, means for varying the relation of the diaphragm relative to the rod, including a sleeve carried by the rod and having expansible end portions one of which is threaded into the diaphragm, and wedging members carried by the rod for expanding the end portions of the sleeve.

9. In a sounding signal of the vibratory type, the combination.- of, a motor, frame members mounting the motor and one of which is apertured to support a trumpet, and an air impeller device comprising, apiston disc, a diaphragm, a motor armature for actuating the diaphragm and disc, a rod supporting the armature and disc and connecting them to the diaphragm, means for varying the relation of the diaphragm and disc relative to the rod comprising, a. sleevecarried by the rod and having expansible end portions threaded each into the disc and diaphragm, wedging members carried by the rod for expanding the end portions of the sleeve, one of said wedging members being threaded upon the rod to lock the diaphragm connections.

10. A sounding signal comprising in combination, a magnet motor providing a core and a cooperating armature, a projector, case members supporting the motor and the projector, an impeller device secured between the case members in cooperable relation with the projector, said impeller device including a diaphragm, a piston disc and means coupling the diaphragm and disc for actuation by the armature, said coupling means comprising a rod, an expansible sleeve on the rod having its end portions threaded into the diaphragm and disc, and means carried by the rod for expanding the sleeve into binding engagement with the diaphragm and disc.

11. A sounding signal comprising in co'mbinak tion, a magnet motor providing a core and-a cooperating armature, a projector, case members supporting the motor and the projector, one of which members is apertured for communication with the projector, a diaphragm secured between the case members, a disc cooperable with the apertured case member for vibrating the air column in the projector, and means for actuating the disc to and from the apertured case member comprising, a rod, a sleeve carried by the rod and threaded throughthe diaphragm and disc, and means including parts carried by the rod for a compression chamber, compression chamber .bers supporting an impeller device secured between thecase' with respect to each securing the sleeve against threadable movement through'the diaphragm and/or disc.

tion, a magnet motor providing a core and a cooperating armature, a projector, case members for themotor one of which is dished to form a shallow chamber opening into the projector, a diaphragm secured between the case members and cooperating with the dished member to form a disc located'in the and cooperable with the dished member to stop the air column throughthe projector, and means for actuating the disc to and from the dished member comprising, an armature, a'spindle device connecting the armature with the diaphragm and including 'the spindle device spaced 'relation between the disc and dished case member.

13. In a sounding signal motor, a projector providing an air column and housing members for enclosing the motor and for supporting the projector; the combination comprising; a movable assembly supported by the housing members and actuatable bythe motor, said assembly comprising, a diaphragm forming a chamber with one of the housing members opening into the projector, clamping discs centrally disposed with respect to the diaphragm and secured thereto, an armature, a rod disc, and means for varying'the,

having a vibration carried by the rod and threaded through the.

clamping discs, a wedging member disposed between the armature and for expanding the sleeve end into firm engageme-nt with the clamping discs, and means carried by the rod for forcing the wedging member into expanding engagement with the sleeve end portion.

the end of the sleeve 14; A sounding signal comprising in combination, a magnet motor providing a core and a cooperating armature; a projector; case memthe motor and the projector;

members in coo-perable relation with the projector, said impeller device including a diaphragm, a piston disc, and a sleeve having ex- .pansible portions coupling the diaphragm and the disc for actuation by the armature; and 50 means including the coupling means for altering the spaced relation of the impeller elements other and the space-d relation of the piston disc and the adjacent case member.

' 15. A sound signal comprising in a magnet motor providing a core and a cooperatcombination';

ing armature; a projector; case members sup porting the core and the projector; device secured between the case members in cooperable relation with the projector, said impeller device including a diaphragm, a piston disc and meanscoupling the diaphragm and disc a resilient support ono-ne side 7 to the armature; Oif the corefor'guiding one end of the coupling means; and means including the coupling means for changing the spaced relation of the impeller elements with respect'to each other.

ROBERT M. CRITCHFIELD.

an impeller 

